This invention is a process for the total manufacture of chewing gum base and chewing gum using a modified high efficiency continuous mixer.
Conventionally, chewing gum base and chewing gum product have been manufactured using separate mixers, different mixing technologies and, often, at different factories. One reason for this is that the optimum conditions for manufacturing gum base, and for manufacturing chewing gum from gum base and other ingredients such as sweeteners and flavors, are so different that it has been impractical to integrate both tasks. Chewing gum base manufacture, on the one hand, involves the dispersive (often high shear) mixing of difficult-to-blend ingredients such as elastomer, filler, elastomer plasticizer, base softeners/emulsifiers and, sometimes wax, and typically requires long mixing times. Chewing gum product manufacture, on the other hand, involves combining the gum base with more delicate ingredients such as product softeners, bulk sweeteners, high intensity sweeteners and flavoring agents using distributive (generally lower shear) mixing, for shorter periods.
In order to improve the efficiency of gum base and gum product manufacture, there has been a trend toward the continuous manufacture of chewing gum bases and products. U.S. Pat. No. 3,995,064, issued to Ehrgott et al., discloses the continuous manufacture of gum base using a sequence of mixers or a single variable mixer. U.S. Pat. No. 4,459,311, issued to DeTora et al., also discloses the continuous manufacture of gum base using a sequence of mixers. Other continuous gum base manufacturing processes are disclosed in European Publication No. 0,273,809 (General Foods France) and in French Publication No. 2,635,441 (General Foods France).
U.S. Pat. No. 5,045,325, issued to Lesko et al., and U.S. Pat. No. 4,555,407, issued to Kramer et al., disclose processes for the continuous production of chewing gum products. In each case, however, the gum base is initially prepared separately and is simply added into the process. U.S. Pat. No. 4,968,511, issued to D""Amelia et al., discloses a chewing gum product containing certain vinyl polymers which can be produced in a direct one-step process not requiring separate manufacture of gum base. However, the disclosure focuses on batch mixing processes not having the efficiency and product consistency achieved with continuous mixing. Also, the single-step processes are limited to chewing gums containing unconventional bases which lack elastomers and other critical ingredients.
In order to simplify and minimize the cost of chewing gum manufacture, there is need or desire in the chewing gum industry for an integrated continuous manufacturing process having the ability to combine chewing gum base ingredients and other chewing gum ingredients in a single mixer, which can be used to manufacture a wide variety of chewing gums.
The present invention provides methods for the continuous manufacture of a wide variety of chewing gum products using a modified high efficiency mixer which does not require the separate manufacture of chewing gum base. It has been found that by shortening, or backing out, one or more hollow feed pins that are typically used in a blade and pin type extruder, greater feed of ingredients can be achieved. Additionally, clogging of feed orifices can be avoided. However, it has also been determined that certain pins cannot be shortened or backed out.
In an embodiment, the present invention provides a method for manufacturing chewing gum comprising the steps of adding chewing gum ingredients to an extruder that includes pins that circumscribe a shaft having blades. Pursuant to the present invention, the extruder includes at least one hollow pin that has a clearance from the shaft of at least 2.7% of the barrel diameter.
In another embodiment, a method for modifying a blade and pin extruder so as to allow it to manufacture chewing gum is provided comprising the steps of increasing the distance between at least one hollow pin and a shaft of the extruder so that the distance is equal to at least 2.7% of the barrel diameter.
In another embodiment, a method of continuously manufacturing chewing gum in a blade and pin extruder is provided, comprising the steps of: a) adding at least an elastomer and filler into a high efficiency continuous mixer; b) adding a least one ingredient selected from the group consisting of fats, oils, waxes and elastomer plasticizers into the continuous mixer, and mixing said ingredient with the elastomer and filler; c) adding at least one sweetener and at least one flavor into the continuous mixer, and mixing said sweetener and flavor with the remaining ingredients to form a chewing gum product; and d) wherein at least one ingredient is added through a hollow pin that is located at a greater distance from a shaft of the extruder then at least one other pin of the extruder.
In still another embodiment, a method of continuously manufacturing chewing gum without requiring the separate manufacture of a chewing gum base is provided, comprising the steps of: a) adding at least an elastomer and filler into a blade and pin continuous mixer; b) subjecting at least the elastomer and filler to mixing in the continuous mixer; c) adding at least one sweetener and at least one flavoring agent into the elastomer and filler in the continuous mixer; d) subjecting at least the sweetener, flavoring agent, elastomer and filler to distributive mixing in the continuous mixer, to form a chewing gum product; e) continuously discharging the chewing gum product from the mixer; and f) wherein at least one ingredient is added to the continuous mixer through a hollow pin located at a distance from the shaft of at least 3% of the diameter of the barrel.
In a further embodiment, a method of continuously manufacturing chewing gum without requiring separate manufacture of a chewing gum base, comprising the steps of: a) adding at least an elastomer and filler into a blade-and-pin mixer that includes hollow pins that are located at different distances from a shaft of the extruder, and mixing the elastomer and filler together using blades and pins; b) adding-at least one ingredient selected from the group consisting of fats, oils, waxes and elastomer plasticizers into the blade-and-pin mixer, and mixing said at least one ingredient with the elastomer and filler using blades and pins; and c) adding at least one sweetener and at least one flavor into the blade-and-pin mixer, and mixing said sweetener and flavor with the remaining ingredients to form a chewing gum product.
A high efficiency continuous mixer is one which is capable of providing thorough mixing over a relatively short distance or length of the mixer. This distance is expressed as a ratio of the length of a particular active region of the mixer screw, which is composed of mixing elements, divided by the maximum diameter of the mixer barrel in this active region. In an embodiment, the method of the invention comprises performing the following mixing steps in a single continuous mixer:
a) adding and thoroughly mixing at least a portion of the chewing gum base ingredients (elastomer, elastomer plasticizer, filler, etc.) in a continuous mixer, using an L/D of not more than about 25;
b) adding at least a portion of the remaining (non-base) chewing gum ingredients (sweeteners, flavors, softeners, etc.), and thoroughly mixing these ingredients with the gum base in the same mixer, using an L/D of not more than about 15; and
c) sufficiently completing the entire addition and mixing operation in the same mixer, so that the ingredients exist as a substantially homogeneous chewing gum mass, using a total L/D of not more than about 40.
It is preferred that the gum base ingredients be completely added and mixed upstream from the remaining chewing gum ingredients, and that the remaining ingredients be completely added downstream for mixing with the already blended gum base. However, the invention also includes those variations wherein a portion of the gum base ingredients may be added downstream with or after some of the remaining ingredients, and/or wherein a portion of the remaining (non-base) ingredients are added upstream with or before some of the base ingredients. An important feature is that a substantially homogenous chewing gum product mass be formed in a single continuous mixer, using an L/D of not more than about 40, without requiring a separate mixer to manufacture the chewing gum base.
With the foregoing in mind, it is an advantage of the invention to provide a continuous method for manufacturing chewing gum which does not require a separate manufacture of chewing gum base.
It is also an advantage of the invention to provide an improved blade and pin extruder for manufacturing chewing gum.
It is also an advantage of the invention to provide a method of reducing, or preventing, clogging of the ingredient addition orifices in an extruder.
It is also an advantage of the present invention to provide a method of injecting increased volumes of liquid ingredients into the extruder.
It is also an advantage of the invention to provide a continuous method for making chewing gum which accomplishes every essential mixing step using a single mixer.
It is also an advantage of the invention to provide a continuous method for making chewing gum which requires less equipment, less capital investment, and less labor than conventional manufacturing methods.
It is also an advantage of the invention to provide a continuous manufacturing method that produces chewing gum having greater product consistency, less thermal degradation, less thermal history, and less contamination than chewing gum produced using conventional processes that require longer manufacturing times and more manufacturing steps.
The foregoing and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying examples and drawings. The detailed description, examples and drawings are intended to be merely illustrative rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.